Evaluation of the performance of VoIP managed by different queuing schemes | |
| Author | Nisa Chatupromwong |
| Call Number | AIT Thesis no.TC-02-03 |
| Subject(s) | Internet telephony TCP/IP (Computer network protocol) |
| Note | A thesis submitted in partial fulfillment of requirements for the degree of Master of Engineering, School of Engineering and Technology |
| Publisher | Asian Institute of Technology |
| Series Statement | Thesis ; no. TC-02-03 |
| Abstract | Voice over Internet Protocol (VoIP) is a real time application on networks using Internet protocol. VoIP application requires timely packet delivery with low delay but the current Best-Effort (BE) Internet service does not differentiate between packets of different applications. Many algorithms are designed to provide scalable quality of service support within the Internet. In this thesis, priority queuing (PQ) and weighted fair queuing (WFQ) algorithms are studied for providing differentiated services and compared to BE algorithm. The performances of Internet traffic, voice, WWW and FTP, are investigated in the simulation model of a network with one bottleneck link and 2 nodes. The performance parameters studied are mean end-to-end delay, voice packet distribution and FTP throughput. Additionally, the effects of varying the voice share of total traffic and link utilization is studied. The effects of different packet size distributions of WWW traffic, Uniform and Pareto distribution, are considered. The simulation results shows that PQ scheme has great positive impact on voice traffic for all algorithms here, where voice average delay is improved by about 52 %. The voice delay distribution of PQ scheme has the smallest delay upper bound about 18 ms. In contrast, PQ algorithm deteriorates the throughput performance of the lowest-priority FTP traffic by about 51 % while the voice share increases especially at the high link utilization. WFQ algorithm improves the voice average delay about 40% but also FTP throughput does not highly suffer, it decrease by only 22% at 100% link utilization. Although the voice packet delay distribution has longer tail than in PQ algorithm, the delay upper bound 23 ms is somewhat lower than 29 ms of delay bound in BE algorithm. As seen from the simulation results, when WWW packet distribution changes from Uniform distribution to Pareto distribution, the properties of performance behavior at the same situation are similar. It is obvious that WFQ algorithm is an algorithm able to improve the quality of voice traffic and does not extremely degrade the quality of the other traffic classes. In the simulation cases the studied WWW packet size distribution resulted in almost equal system performances. |
| Year | 2002 |
| Corresponding Series Added Entry | Asian Institute of Technology. Thesis ; no. TC-02-03 |
| Type | Thesis |
| School | School of Engineering and Technology (SET) |
| Department | Department of Information and Communications Technologies (DICT) |
| Academic Program/FoS | Telecommunications (TC) |
| Chairperson(s) | Erke, Tapio; |
| Examination Committee(s) | Ahmed, Kazi M. ;Kanchana Kanchanasut; |
| Scholarship Donor(s) | Telephone Organization of Thailand (TOT); |
| Degree | Thesis (M.Eng.) - Asian Institute of Technology, 2002 |